Power Brake Booster location

I have been watching "CAR S.O.S." TV show which is made in UK. I'm in USA. A car with power brakes have boosters mounted on the firewall with pedal on one end and master cylinder on other end. On the TV show when they converted two cars from manual to power brakes, they put the boosters somewhere else in the engine compartments. How do the boosters work?

yes, we found this on amazon, you also can find there which is you want

I've seen some modifications for hot rods and the like where the power brake booster is mounted under the floor or directly to the frame below the level of the brake pedal. In those installations a lever is connected between the brake pedal and the brake booster versus the more typical straight pushrod that goes directly from the brake pedal to the booster piston. For the standard vacuum assist power brake booster, as long as you have a way to linearly depress the booster piston and can route a vacuum line to the booster, you can mount it where convenient. Fabricators can get pretty creative and artistic when it comes to designing linkages....

-Rod